Methods and apparatus for selecting a communication network

ABSTRACT

Methods and apparatus for selecting a cellular network to provide one or more communication services for a mobile communication device are disclosed. A scanning operation is performed by the mobile device to identify a plurality of cellular networks that support a voice communication service in a geographic coverage area. The mobile device then identifies which of the cellular networks makes a data communication service available to it. Advantageously, the mobile device assigns priority to or selects a cellular network that makes the data communication service available over a network that fails to make the data communication service available, and may register with that network. The data communication service may include, as examples, an e-mail communication service or an Internet access service. Preferably, the cellular network operates in accordance with GSM (Global System for Mobile) and GPRS (Generalized Packet Radio Service).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to a U.S. provisional patentapplication entitled “Methods And Apparatus For Selecting ACommunication Network For A Wireless Communication Device” having U.S.Ser. No. 60/422,124 and a filing date of Oct. 30, 2002.

BACKGROUND

1. Field of the Technology

The present invention relates generally to mobile communication devices,such as portable wireless e-mail devices operating over cellulartelecommunications networks, and more particularly to a method ofselecting a communication network over which to operate based on theavailability of different communication services in the communicationnetworks.

2. Description of the Related Art

A mobile communication device, such as a cellular mobile station, may becapable of making and receiving telephone calls and/or sending andreceiving data over a wireless communication network. Before it is ableto do this, the cellular mobile station selects and registers with oneof a plurality of communication networks which are available within agiven geographic coverage area. After registering with the selectednetwork, the mobile station operates in an idle mode where it “camps-on”a particular wireless communication channel of the network to monitorfor its calls or messages. “Network selection” is the particular processperformed by the mobile station for selecting the one communicationnetwork over which to register and operate.

Cellular telephony operation and network selection schemes aredocumented in standards specifications that govern the behavior ofcellular mobile stations and associated systems. One well-known cellularstandard is the Global System for Mobile Communication (GSM) standard.GSM 03.22/European Technical Standards Institute (ETSI) TX 100 930,Technical Specification (TS) 23.122 from the 3^(rd) GenerationPartnership Project (3GPP), and other related standards specificationsdescribe the many details of cellular operation and network selection.These documents describe how a mobile station behaves as it roamsbetween various regions and countries to maintain communication networkcoverage, primarily for the purposes of providing continuous telephoneservice.

In such a network, a mobile station performs network selection byinitially determining the signal strengths of each one of the availablebase stations in a given coverage area. Thereafter, it searches forthese identified base stations within a preferred network list that isstored in memory. The mobile station then selects the base station withstrongest signal that is listed in the preferred network list. There maybe several preferred network lists, commonly referred to as preferredpublic land mobile network (PPLMN) lists, stored on the SIM card. Forexample, the PPLMN lists may include a home PPLMN list, auser-controlled PPLMN (U-PPLMN) list, and an operator-controlled PLMN(O-PPLMN) list.

The above-described network selection method is commonly referred to asan “automatic” network selection method. As an alternative to thisautomatic selection method, an end-user of the mobile station may beprovided with the ability to manually select from a plurality of listedavailable networks which are visibly displayed on the mobile device.This conventional network selection method may be referred to as a“manual” network selection method.

Other portable devices, such as personal digital assistants (PDAs),laptop computers, and portable e-mail devices, are better known toprovide for the organization and management of text, files, messages,and/or other data. However, mobile data communication services, such aswireless e-mail and Internet access services, are becoming more and morepopular in connection with these devices. Mobile devices providing forcombined capabilities (e.g. both voice and data communication) alsoexist and are becoming increasingly popular. In addition to operating inaccordance with GSM for voice capabilities, these mobile devices mayoperate in accordance with well-known General Packet Radio Service(GPRS) standard. GPRS is a packet-based communication protocol formobile devices that allows data to be sent and received across a mobiletelephone network.

In order to operate fully as intended, these mobile devices must havethe appropriate communication services supported and made available bythe communication network that it is registered with. Ideally, allcommunication networks around the world should support and makeavailable all the different types of communication services that amobile device is capable of providing. In practice, however, somecommunication networks do not have or cannot make a particularcommunication service (e.g. a data communication service) available to amobile device. This problem may be partially mitigated in a givencoverage area as there may be several communication networks from whichthe mobile device may select.

Conventional network selection, however, does not take intoconsideration the availability of other services (e.g. datacommunication services) in its decision-making process. As a result, aninadequate communication network may be selected by the mobile device.For example, a mobile device may select a communication network that canprovide an acceptable voice service but not a data service, even thoughanother adequate and available network could provide both the voice andthe data service. Such conventional operation is undesirable, especiallyfor mobile devices that are primarily intended to provide the end-userwith a data communication service (e.g. portable e-mail devices).

Accordingly, there is a resulting need for a method and apparatus forselecting a communication network that overcome the deficiencies of theprior art.

SUMMARY

The present application describes methods and apparatus for selecting acommunication network to provide one or more communication services fora mobile communication device. A scanning operation is performed by themobile device to identify a plurality of communication networks whichsupport a voice communication service in a geographic coverage area. Themobile device then determines which of the communication networks make adata communication service available for the mobile device in thegeographic coverage area. Advantageously, the mobile device selects andregisters with a communication network that makes the data communicationservice available over a network that fails to make the datacommunication service available. Preferably, the mobile communicationdevices operate in accordance with GSM (Global System for Mobile) andGPRS (Generalized Packet Radio Service). Also preferably, the method isperformed in connection with the creation of one or more prioritizednetwork lists. In this case, the mobile device assigns a higher priorityin the prioritized network list to a communication network that makesthe data communication service available over a communication networkthat does not make the data communication service available.

The method may be more generalized to involve a mobile communicationdevice which identifies a plurality of communication networks availableto facilitate mobile communications with the mobile device in ageographic coverage area; identifies one or more communication servicesthat are actually made available to the mobile device in each network;determines which network provides the best communication services forthe mobile device based at least in part on the identified availabilityof services in each network; selects or assigns priority to the networkthat is determined to provide the best services for the mobile device;and registers with the selected or prioritized network. Thecommunication services which may be made available by the networksinclude, but are not limited to, a voice communication service, anelectronic mail (e-mail) service, a short messaging service (SMS), anInternet access service, a private Intranet access service, a wirelessapplication protocol (WAP) service, a local data facilitating service, ahome data facilitating service, and application-specific data servicessuch as a weather service, a horoscope service, and a stock marketquotations service.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a global network interconnection;

FIG. 2 is a block diagram of a mobile communication device which is acellular mobile station;

FIG. 3 is a block diagram showing two GSM/GPRS networks and a mobilestation roaming between them;

FIG. 4 is a block diagram illustrating a mobile station in a regionwhere there are several communication networks of different types;

FIGS. 5 and 6 form a flowchart which describes a method of creating aprioritized network list in accordance with the present application;

FIG. 7 is a flowchart which describes a rescanning method in accordancewith the present application;

FIG. 8 is a flowchart which describes an alternate rescanning method;and

FIG. 9 is a flowchart which describes an alternative method of networkselection in accordance with the present application.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Methods and apparatus for performing network selection by a mobilecommunication device are described herein. In situations where more thanone wireless network is available in a given coverage area, a method ofassigning priority to or selecting a wireless network that provides the“best” services for the mobile station is employed. Such methods areapplicable to mobile devices that operate in accordance with anysuitable communication standard, but are particularly applicable toadvanced GPRS-capable mobile stations. In this environment, the methodmay place a priority on selecting a GPRS-capable network over a GSM-onlycapable network.

An advanced network selection method in a mobile communication devicemay involve determining that it has changed network coverage regions;identifying the presence of new communication networks having suitablesignal strength in the new coverage region; determining which of the newnetworks support a data communication service used by the mobile device;comparing the new networks against preferred and forbidden networklists; and selecting the best communication network with which toregister and operate. The selection may be based upon (a) comparing thesignal strength of all communication networks; (b) attempting to matchthe new networks to a network on the preferred list; (c) identifyingthat the data network is not on the forbidden list or that thecommunication network is not on either list; and (d) confirming thelevel of support offered by the communication network.

Where the mobile communication device has been forced to select anetwork that supports only limited services (e.g. only a voicecommunication service), further methods for selecting or prioritizing acommunication network may be used. When a mobile communication device iscurrently using a voice-only network, for example, an advanced networkreselection method is employed which may involve (a) ensuring that arescan timer is set; (b) when the rescan timer expires, performing asearch for any new communication network that was not previouslyavailable; (c) determining if the new network makes better communicationservices available than the voice-only network; (d) confirming that thenew network is either on the preferred network list, not on theforbidden network list, or not on either list; and (e) selecting the newnetwork for registration.

With reference now to FIG. 1, an overview of how networks connect aroundthe world will be described. GSM and GPRS networks are shown as examplewireless communication networks. The voice network known as GSM is theolder component and has been available since about 1992 while GPRS, adata component that has been combined or overlaid with GSM, has beenavailable only since about 1999. These two networks are now commonthroughout the world and have some of the fastest deployment rates ofany voice and data networks. Such combined voice and data networks alsoinclude modem Code Division Multiple Access (CDMA) networks andthird-generation (3G) networks like Enhanced Data-rates for GlobalEvolution (EDGE) and Universal Mobile Telecommunications Systems (UMTS),currently under development.

In FIG. 1, there are five GSM only networks 10, 14, 16, 22, 26 and eightGSM/GPRS combined networks 2, 4, 8, 12, 18, 20, 24, 28, shown in variousparts of the world. At any point in time, a given country might have oneor more GSM and/or GSM/GPRS networks. Each network operator makesfinancial and practical decisions as to when it should purchase andimplement GPRS functionality onto an existing GSM network. Therefore, auser of a GSM phone or a GPRS capable mobile station might enter a givencountry and be faced with networks that support either GSM only orcombined GSM/GPRS.

These networks implement interconnections to each other to supportroaming between countries and to support billing and roamingnotifications between networks. Although shown as separate physicalnetworks in FIG. 1, the thirteen networks (five GSM and eight GSM/GPRS)interconnect to form a total of four networks—three GSM/GPRS networks 1,2, and N, and one GSM network 1. A GSM network could connect to one ormore other GSM networks, one or more GSM/GPRS networks, or both. AGSM/GPRS network could similarly connect with other GSM/GPRS networks,GSM networks, or both GPRS/GSM networks and GSM networks. Networks inCanada, shown as GSM/GPRS1 2 and GSM/GPRS2 4, respectively connect withGSM/GPRS1 12 and GSM1 14 shown in the USA. GSM/GPRS2 4 also connectswith GSM/GPRS1 8 shown in the England area via communication link 6.Network GSM1 14 from the USA also connects with GSM1 10 shown in themiddle of Europe. Other networks 16 through 28 are similarlyinterconnected as shown. These interconnections form the basis oftraffic movement and roaming support between the networks.

As a mobile station enters a given country or communication networkcoverage area, it may be capable of communicating with one or morewireless GSM or GSM/GPRS networks to receive data and voice signals. InEngland, for example, there are currently four GSM or GSM/GPRS networksdeployed and available for mobile stations to connect with. Normally,cellular telephones or mobile stations sold in England will only workwith one network. However, mobile stations entering England from Francemight have two or three networks to select from. Selection of aparticular network is currently performed by a mobile station randomly,based on the strongest received signal at the time of arrival into thecountry.

Turning now to FIG. 2, a block diagram is shown of a cellular mobilestation, which is one type of mobile communication device. Mobilestation 115 is preferably a two-way wireless communication device havingat least voice and data communication capabilities. Mobile station 115preferably has the capability to communicate with other computer systemson the Internet. Depending on the exact functionality provided, themobile device may be referred to as a data messaging device, a two-waypager, a wireless e-mail device, a cellular telephone with datamessaging capabilities, a wireless Internet appliance, or a datacommunication device, as examples.

Where mobile station 115 is enabled for two-way communication, it willincorporate a communication subsystem 211, including both a receiver 212and a transmitter 214, as well as associated components such as one ormore, preferably embedded or internal, antenna elements 216 and 218,local oscillators (LOs) 213, and a processing module such as a digitalsignal processor (DSP) 220. As will be apparent to those skilled in thefield of communications, the particular design of the communicationsubsystem 211 will be dependent upon the communication network in whichthe device is intended to operate. For example, mobile station 115 mayinclude a communication subsystem 211 designed to operate within theMobitex™ mobile communication system, the DataTAC™ mobile communicationsystem, or a GPRS network.

Network access requirements will also vary depending upon the type ofnetwork 219. For example, in the Mobitex and DataTAC networks, mobilestation 115 is registered on the network using a unique identificationnumber associated with each mobile station. In GPRS networks, however,network access is associated with a subscriber or user of mobile station115. A GPRS mobile station therefore requires a subscriber identitymodule (SIM) card in order to operate on a GPRS network. Without a validSIM card, a GPRS mobile station will not be fully functional. Local ornon-network communication functions, as well as legally requiredfunctions (if any) such as “911” emergency calling, may be available,but mobile station 115 will be unable to carry out any other functionsinvolving communications over the network 219. The SIM interface 244 isnormally similar to a card-slot into which a SIM card can be insertedand removed. The SIM card can have approximately 64K of memory and holdmany key configuration, identification, and subscriber relatedinformation 250. The O-PPLMN, the U-PPLMN, and the forbidden PLMN(FPLMN) are initially received from the SIM card 250. Reference to thePPLMN hereinafter will generally apply to both the O-PPLMN and U-PPLMN.

When required network registration or activation procedures have beencompleted, mobile station 115 may send and receive communication signalsover the network 219. Signals received by antenna 216 throughcommunication network 219 are input to receiver 212, which may performsuch common receiver functions as signal amplification, frequency downconversion, filtering, channel selection and the like, and in theexample system shown in FIG. 2, analog to digital (A/D) conversion. A/Dconversion of a received signal allows more complex communicationfunctions such as demodulation and decoding to be performed in the DSP220. In a similar manner, signals to be transmitted are processed,including modulation and encoding for example, by DSP 220 and input totransmitter 214 for digital to analog conversion, frequency upconversion, filtering, amplification and transmission over thecommunication network 219 via antenna 218. DSP 220 not only processescommunication signals, but also provides for receiver and transmittercontrol. For example, the gains applied to communication signals inreceiver 212 and transmitter 214 may be adaptively controlled throughautomatic gain control algorithms implemented in DSP 220.

Mobile station 115 preferably includes a microprocessor 238 whichcontrols the overall operation of the device. Communication functions,including at least data and voice communications, are performed throughcommunication subsystem 211. Microprocessor 238 also interacts withfurther device subsystems such as the display 222, flash memory 224,random access memory (RAM) 226, auxiliary input/output (I/O) subsystems228, serial port 230, keyboard 232, speaker 234, microphone 236, ashort-range communications subsystem 240 and any other device subsystemsgenerally designated as 242.

Some of the subsystems shown in FIG. 2 perform communication-relatedfunctions, whereas other subsystems may provide “resident” or on-devicefunctions. Notably, some subsystems, such as keyboard 232 and display222, for example, may be used for both communication-related functions,such as entering a text message for transmission over a communicationnetwork, and device-resident functions such as a calculator or tasklist.

Operating system software used by the microprocessor 238 is preferablystored in a persistent store such as flash memory 224, which may insteadbe a read-only memory (ROM) or similar storage element (not shown).Those skilled in the art will appreciate that the operating system,specific device applications, or parts thereof, may be temporarilyloaded into a volatile memory such as RAM 226. Received communicationsignals may also be stored in RAM 226.

Microprocessor 238, in addition to its operating system functions,preferably enables execution of software applications on the mobilestation. A predetermined set of applications that control basicoperations, including at least data and voice communication applicationsfor example, will normally be installed on mobile station 115 duringmanufacturing. A preferred software application may be a personalinformation manager (PIM) application having the ability to organize andmanage data items relating to the user of the mobile station such as,but not limited to, e-mail, calendar events, voice mails, appointments,and task items. Naturally, one or more memory stores would be availableon the mobile station to facilitate storage of PIM data items. Such PIMapplication would preferably have the ability to send and receive dataitems, via the wireless network 219. In a preferred embodiment, the PIMdata items are seamlessly integrated, synchronized and updated, via thewireless network 219, with the mobile station user's corresponding dataitems stored or associated with a host computer system. Furtherapplications may also be loaded onto the mobile station 115 through thenetwork 219, an auxiliary I/O subsystem 228, serial port 230,short-range communications subsystem 240 or any other suitable subsystem242, and installed by a user in the RAM 226 or preferably a non-volatilestore (not shown) for execution by the microprocessor 238. Suchflexibility in application installation increases the functionality ofthe device and may provide enhanced on-device functions,communication-related functions, or both. For example, securecommunication applications may enable electronic commerce functions andother such financial transactions to be performed using the mobilestation 115.

In a data communication mode, a received signal such as a text messageor web page download will be processed by the communication subsystem211 and input to the microprocessor 238, which preferably furtherprocesses the received signal for output to the display 222, oralternatively to an auxiliary I/O device 228. A user of mobile station115 may also compose data items such as email messages for example,using the keyboard 232, which is preferably a complete alphanumerickeyboard or telephone-type keypad, in conjunction with the display 222and possibly an auxiliary I/O device 228. Such composed items may thenbe transmitted over a communication network through the communicationsubsystem 211, and stored in portions 251 of flash memory 224.

For voice communications, overall operation of mobile station 115 issimilar, except that received signals would preferably be output to aspeaker 234 and signals for transmission would be generated by amicrophone 236. Alternative voice or audio I/O subsystems, such as avoice message recording subsystem, may also be implemented on mobilestation 115. Although voice or audio signal output is preferablyaccomplished primarily through the speaker 234, display 222 may also beused to provide an indication of the identity of a calling party, theduration of a voice call, or other voice call related information forexample.

Serial port 230 in FIG. 2, shown as 115 in FIG. 1, would normally beimplemented in a personal digital assistant (PDA)-type mobile stationfor which synchronization with a user's desktop computer (not shown) maybe desirable, but is an optional device component. Such a port 230 wouldenable a user to set preferences through an external device or softwareapplication and would extend the capabilities of mobile station 115 byproviding for information or software downloads to mobile station 115other than through a wireless communication network. The alternatedownload path may for example be used to load an encryption key onto thedevice through a direct and thus reliable and trusted connection tothereby enable secure device communication.

A short-range communications subsystem 240 is a further optionalcomponent which may provide for communication between mobile station 115and different systems or devices, which need not necessarily be similardevices. For example, the subsystem 240 may include an infrared deviceand associated circuits and components or a Bluetooth™ communicationmodule to provide for communication with similarly-enabled systems anddevices.

FIG. 3 is a block diagram showing two GSM/GPRS networks and a mobilestation roaming between them. FIG. 3 depicts a mobile station 115roaming between two GSM/GPRS networks 120 and 125. This type of roamingarrangement is similar to how a GSM-only network might handle roaming,but with minor differences. In a GSM/GPRS combined network, a mobilestation that supports only voice, only data, or a combination of voiceand data will be treated similarly with respect to roaming betweennetworks. A mobile station entering a given area or country can detectthe GSM and GSM/GPRS networks through special RF radio channelinteractions. The illustration of FIG. 3 provides a quick referencesummary to describe how the process works. Roaming relationships betweenoperators are established mainly for billing issues. Special Interoperator tariff (IoT) arrangements can be established between operatorsfor GSM traffic only, or GSM and GPRS traffic. It is these relationshipsthat are reflected in the PPLMN and FPLMN lists within the mobilestation SIM cards.

GSM/GPRS Network 1 is the home network 120 for the user of mobilestation 115. The home network for the user is referred to as the homepublic land mobile network (HPLMN) and mobile stations registered withinthat network are maintained in a home location registry (HLR) 150. HLR150 is used to verify subscribers on the home network, and to confirmhome subscribers on other networks. Each wireless network supports arange of services where each of the service access points tends to be afixed connection, not a radio-based connection. Fixed connectionsgenerally allow greater capacity of data throughput for a large numberof service subscribers supported by a single Access Point Name (APN). InFIG. 3, one such service is termed a home service provider 100, as itmight be the primary communications service for a given group of mobilestations 115. Some mobile stations 115 might have a single home serviceprovider 100, or they might have several services 105, 110 that theyaccess.

The main components in GSM/GPRS network 125 include base station 145,the serving GPRS support node (SGSN) 130, the gateway GPRS support node(GGSN) 140, the Border GGSN node 135, the HLR (home location registry)150 and the VLR (visitor location registry) 155.

Conventionally, when mobile station 115 is within a coverage area ofhome network 120, it communicates via base station 145 back throughnetwork 120 to home service provider 100. When mobile station 115 islooking for coverage, especially when there might be several networksavailable, it normally checks for the HPLMN first. As the user roams toanother country or region where home network 120 is no longer available,mobile station 115 scans for all available base stations 145 viareceived, normally radio frequency (RF), signal strengths. To oneskilled in the art, it is understood that selecting a ‘strong enough’ RFsignal strength is open to a wide range of settings and interpretations.As an example, the GSM standards specify that a signal strength of −85dBm or more should be considered an appropriate level for a ‘strongenough’ signal. However, this exact signal level is not essential to thesystems and methods described herein, and other values may be useful,depending upon the particular network, mobile station or type of networkor mobile station.

Those skilled in the art will appreciate that such scanning processeshave pre-defined patterns. In a GSM or GPRS network, for example,scanning operations are defined in the standards governing GSM mobilestations. There is some flexibility in the standards, allowing a user tohave some participation in the selection of a network to be used outsideof the HPLMN. Each network is defined as a PLMN, and the relationshipbetween PLMNs can be defined in tables within mobile station 115. Oncemobile station 115 has identified base stations 145 and thus thenetworks within its range, it turns to the PPLMN list to see if one ofthe networks matches a network in the PPLMN list.

In conventional GPRS mobile stations, there are two types of PPLMN listswithin the mobile station 115, namely an O-PPLMN and a U-PPLMN as shownin FIG. 2. The user-defined list is a relatively new concept and is inlimited use at the current time. Similarly, mobile station 115 also hasa Forbidden PLMN (FPLMN) list which it uses to exclude certain networkconnections. There is also a chance that a network located during ascanning operation does not fall into either of these lists. In thiscase, the network can preferably still be used in response to aconfirmation by a mobile station user, through a dialog box for example,as to which network should be used.

GPRS networks are normally linked through a GPRS routing exchange (GRX)160 and a border GGSN 135. The signaling involved with this exchange isdescribed herein to the extent necessary to illustrate aspects of theinvention. Further details of GRX 160 may be apparent to those skilledin the art, and can also be found in the GSM specifications dealing withsupport for roaming in GPRS (GSM specification 23.122).

When mobile station 115 experiences a prolonged out-of-coveragesituation, it begins to look for RF signals from base stations 145. Oncea signal is acquired, the radio protocols inform mobile station 115which network has been reached and the capabilities of that network.Each network has a signature, and a GPRS-capable base station has anextended handshake protocol beyond the GSM protocol to identify its datacapabilities. Within a GSM/GPRS network there exists a mobile countrycode (MCC) and a mobile network code (MNC) which contains a networkassigned value and an access technology number. The access technologynumber indicates the radio frequency range of the network, i.e. 900 MHz,1800 MHz, 1900 MHz, etc.

As mobile station 115 selects a network, it performs an “attach” to thenetwork and provides its identification code. For GSM/GPRS, this codecould include both the International Mobile Subscriber Identity (IMSI)or Temporary Mobile Subscriber Identity (TMSI), which identify acommunication network account or subscription, and a Mobile StationISDN/PSTN Number MSISDN, which identifies the mobile station user orsubscriber. If mobile station 115 is attempting to attach to a networkother than its home network 120, such as network 125, then the othernetwork 125 will use the GRX network 160 to verify the subscription withhome network 120. This causes home network 120 to reference HLR 150 todetermine if the subscription is valid. Once verified, mobile station115 is placed in VLR table 155 of visiting network 125. To one skilledin the art, this procedure is similar in a GSM-only network, except thatthe link between the home and visiting networks would be through aGateway Mobile Switching Center (MSC) component.

After attaching to network 125, mobile station 115 will attempt to opena Packet Data Protocol (PDP) context to home service provider 100through the local SGSN 130 in GSM/GPRS network in country-2 125. The PDPcontext targets an APN and home service 100. The PDP context alsoallocates an IP address for mobile station 115 so that IP packets can betransmitted in either direction. SGSN 130 detects mobile station 115 asa visiting mobile station 115 and routes the request through border GGSN135 and onward to the correct GRX connection in GRX network 160 to acorresponding border GGSN 135 in home network 120. As mentioned above,this determination is made by the identification information provided bymobile station 115 during the attach process.

Each interface in the GSM/GPRS network is labeled to identify whichprotocol is used. Between all base stations 145 and SGSN 130, is the Gbinterface. Between SGSN 130 and GGSN 140 is the Gn interface, which isalso used between SGSN 130 and border GGSN 145. Between GGSN 140 and allservice providers, the Gi interface is used, and between border gateways135 and GRX network 160, the Gp interface is used. From GRX network 160,all other foreign network operators (FNO) systems 165 can be reached,assuming they have commonly linked GRX networks.

GSM network standards specify particular steps that mobile station 115must perform to select a base station 145 in GSM/GPRS network incountry-2 125. First, mobile station 115 must achieve a certain minimumlevel of signal strength with the base station. Once signal strength isestablished and the networks associated with each base station whichmeet the minimum signal strength criterion are identified, mobilestation 115 uses its PPLMN and FPLMN lists on the SIM to determine whatit considers the “best” network choice. Mobile station 115 checks thePPLMN list to see if one of the newly located networks matches a networkon the PPLMN list. Similarly, mobile station 115 also checks the FPLMNlist to determine which networks are forbidden. If any of the newlylocated networks occur in the FPLMN, then those networks are excludedfrom any further connection operations. If there are no matches to thePPLMN list, mobile station 115 may attempt to select one of the recentlylocated networks based on signal strength.

FIG. 4 is a block diagram illustrating a mobile station in a regionwhere there are several networks of different types. In FIG. 4, mobilestation 115 is shown in a region with four networks 210, 215, 220, 225,each having a base station 212, 214, 216, 218. For illustrativepurposes, it is assumed that each base station 212, 214, 216, 218 hassimilar RF strength from the point of view of mobile station 115, andthat mobile station 115 receives “strong enough” signals, from LocalNetwork 1 210, Local Network 2 215, Local Network 3 220, and LocalNetwork 4 225. Two of the networks 210 and 215 are GPRS capable and twoof the networks 220 and 225 are GSM-only networks that are not GPRScapable.

According to the present application, in order for mobile station 115 tomaximize its capabilities as a multi-functional mobile station (e.g.capable of both data and voice communication services), it should selectone of the GPRS networks 210 and 215. In conventional GSM operation,mobile station 115 would compare all networks from which receivedsignals are above any minimum required signal strength level and matchthem against the top-most network found in the PPLMN. Since the PPLMN isin priority order, a GSM mobile station must, by definition, follow theordering of this list. In FIG. 4, for example, if Local Network 4 225 isthe highest network listed in the PPLMN list then mobile station 115must camp on this network. However, this process ignores the fact thatmobile station 115 might also be data-capable. The choice of LocalNetwork 4 225, which does not support data communications, may thereforenot always be optimal for mobile station 115.

To improve the capabilities of mobile station 115, the search for abetter network preferably takes other factors into consideration. Sincemobile station 115 cannot effectively communicate when signal strengthis below a certain level, only network base stations with ‘strongenough’ signals are located, substantially as described above. Accordingto one aspect of the invention, data-capable networks, such as GPRSnetworks, are then identified. Mobile station 115 may then determinewhich of the identified data-capable networks is listed first on apreferred network list, which in GSM/GPRS mobile stations would be thePPLMN list. Mobile station 115 then checks to ensure that aninterconnection, such as a GRX network for a GPRS network, is availableto the home network from this highest-priority data-capable network onthe preferred list. If no interconnection to the home network from thehighest priority data-capable network is available, then mobile station115 continues to try the identified data-capable networks that are alsoin the preferred list until a link is found back to the home network.

If no links can be found that connect to the home network, then mobilestation 115 may revert to traditional network selection of anon-data-capable network such as a GSM network, as described above.Alternatively, the network selection method might stop after scanningall data-capable networks for links to the home network. This may beparticularly desirable when the data-capable networks have morecapabilities compared to a non-data-capable network. In somecircumstances, even if a user cannot reach their home network, they maybe able to better use the mobile station on the new network, forexample, to access the Internet at large.

Referring again to FIG. 4, mobile station 115 normally has access to apreferred network list in the form of a PPLMN stored on a SIM card.Data-capable networks include the GSM/GPRS Local Networks 1 and 2, 210and 215, whereas the GSM Local Networks 3 and 4, 220 and 225, representexamples of non-data-capable networks.

If mobile station 115 performs the network selection method describedbriefly above, and it is assumed that the PPLMN list follows theordering of the networks shown in FIG. 4, the first network that shouldbe attempted is the Local Network 1 210. However, since Local Network 1210 does not have a GRX connection back to the home PLMN 205, LocalNetwork 2 215 will be tried next. Since this network does have a Gp link240 back to home PLMN 205 and home service provider 200, it will beselected by mobile station 115. If Local Network 2 215, the lastavailable data-capable network, did not have a connection back to homePLMN 205, the first GSM network would be tried. The first GSM networktried would be Local Network 3 220, and link 230 would be used tocommunicate with the HLR in that home PLMN 205 to verify the user'saccount information. If that fails, Local Network 4 225 would be triedvia link 235.

In another embodiment of FIG. 4, the new networks 210, 215, 220, 225 arenot included on the O-PPLMN list on mobile station 115. This situationis more difficult, as the U-PPLMN list may come into effect, if itexists, in a memory such as the Flash memory 224 or the RAM 226 (FIG.2).

One common way to build up a U-PPLMN is through previous user or“manual” network selections. As in the above example of FIG. 4, it isassumed that mobile station 115 has entered a country or region where itreceives signals of similar strengths from the four networks 210, 215,220 and 225. However, it is further assumed that these networks are notfound on the O-PPLMN list or the FPLMN list, so mobile station 115 mayconsider them to be usable. In this situation, once these networks areidentified, the user may be prompted to choose which network they wouldlike to try. In the GSM specifications this is referred to as manualnetwork selection. After the user has selected a network, it is triedfor connectivity back to home network 205 and, if successful, it isadded to the U-PPLMN.

The user interface (UI) to these manual network selections could be astandard dialog box, a pick list, a scrolling menu, or any other UIselection models available. It will be apparent to those skilled in theart that the UI could also include the network capabilities by showingcapability identifying strings such as “GPRS” or “GSM” beside each ofthe network choices for the user. In another embodiment, the user mightbe presented with a dialog box entitled “GPRS Network Selections”followed by “GSM Network Selections” if all the GPRS networks failed toreach the home PLMN.

Network selection in this situation could instead be automatic, notrequiring user intervention. In such a method, mobile station 115preferably identifies the networks that support GSM and those thatsupport GSM/GPRS and separates the two types of networks. The GSM-onlynetworks are placed on a Discouraged PLMN list (DPLMN) and are onlytried after all the GSM/GPRS networks have been tried and failed. Theonly failure mentioned thus far was around the inability to reach homePLMN 205. Other failures could include: (1) PLMN not allowed; (2)roaming not allowed in this local area; (3) GPRS not allowed; or (4)home network rejection. These errors and others might cause the networkto be placed on the FPLMN, as the network link does not seem to beworking for mobile station 115.

Manually or automatically selected networks are preferably added to theU-PPLMN list, which may be stored in a writable data store such as Flashmemory 224 or RAM 226 (FIG. 2) in mobile station 115. The U-PPLMN listmay then be consulted during subsequent network selection procedures.Normally, mobile station 115 will first check the O-PPLMN list for newnetworks detected during a network selection process before consultingthe U-PPLMN list. It may also be possibly to configure a mobile stationto check the U-PPLMN list before the O-PPLMN list, depending, forexample, upon restrictions controlled by the home network operator, ahome service provider, or a mobile station owner.

Rescanning. According to current GSM specifications, a mobile stationhas only the limited ability to rescan for a network that is higher inpriority on the U-PPLMN list or the O-PPLMN list. If a voice-only GSM orotherwise limited service has been established for a mobile station,however, it may be desirable for the mobile station to periodicallycheck for a new network such as a GSM/GPRS network. This may be doneeven if the network has a lower priority on the O-PPLMN and U-PPLMNlists. This situation may also arise for other types of mobile stationsand networks, where a mobile device is enabled for communications overdifferent types of networks which support different mobile stationfunctions or services.

In FIG. 4, mobile station 115 enters a new region or country and findscoverage (i.e. a ‘strong enough’ signal) with only one GSM-only basestation located on Local Network 4 225. However, as mobile station 115travels within the same country it may come into coverage of anotherGSM/GPRS base station, in Local Network 1 210. In GSM standards, mobilestation 115 could only camp on the network 210 if it had higher priorityin the PPLMN lists. In accordance with the present application, however,mobile station 115 will attempt to rescan for other data-capablenetworks not previously seen or available upon expiration of a timeperiod or other suitable event. This includes any network that may belower in priority on the O-PPLMN and U-PPLMN lists. This time intervalmay be specified or configured by a network operator, SIM manufacturer,network specifications, mobile station manufacturers, or a user ofmobile device 115, as examples. The goal of such rescanning is toimprove the network capabilities of mobile station 115. In this example,mobile station 115 has voice support through the Local Network 4 225,but by changing network connections mobile station 115 could obtain dataand voice support through Local Network 1 210.

A rescanning process may be triggered or initiated by any suitableevent. For example, in the case of an interval timer, a rescanningprocess may be executed whenever a rescan timer expires. Such a timer isreset appropriately so that rescanning is performed at intervals. If thetimer is reset to the same value unless or until the time interval isreconfigured, rescanning will occur at regular intervals. Rescan timingcould instead be repeated at different intervals, if the timer is resetto different values after some number of unsuccessful rescan operationsduring which no new data-capable network is found. In order to avoidrescanning at typically high network traffic times, rescanning couldalso be restricted during certain times of day. Rescanning could also oralternatively be performed when a mobile station detects a change inregions, or when a mobile station acquires a voice-only networkconnection in new region. If the mobile station detects an availablenetwork capable of both voice and data communications, then the mobilestation preferably attempts to camp on this network. Received signalstrengths and PPLMN lists may be used substantially as described aboveduring a rescan process. Since a primary goal of the rescanning processis to find an available data communication service for the mobilestation, rescanning is preferably disabled when a mobile station isalready operating within a network which has the data communicationservice already available.

When a current network is on the O-PPLMN list or the U-PLMN list, and anewly discovered network is not on the PPLMN list, the mobile stationmay remain on the current network instead of switching to a new network.It is likely that most GSM/GPRS networks have been included somewhere onthe O-PPLMN list or possibly the U-PPLMN list. A network change during arescan process may also be dependent upon relative signal strengths toavoid switching from a strong GSM network to a significantly weakerGSM/GPRS network. Acceptable signal strength differences may be stored,for example, in a memory of a mobile station.

Network Selection Using PLMN Lists. FIGS. 5–6 form a flowchart showing amethod of selecting a network for use with a mobile station. The methodshown in these figures relates to GSM/GPRS mobile stations and GSM andGSM/GPRS networks, although the method may be applied in otherenvironments in which mobile stations and networks offering differentkinds and levels of services exist. The method steps shown in FIGS. 5–6may be implemented, for example, primarily in software on a mobilestation.

In step 300 of FIG. 5, the mobile station detects that it has left aregion where the HPLMN is available. This could be a national roamingsituation or an international roaming situation. On the other hand, themobile station may detect an expiration of a rescan timer in step 301.In response to either of these conditions, the mobile station scans forall networks in range at step 305 with the goal of establishing aprioritized list of networks. Each network identified will be tested atstep 310 to ensure that the network is not found on the FPLMN list. Ifthe network is on the FPLMN list, it is ignored, and a test is performedat step 315 to determine if any other networks previously identified instep 305 remain to be checked against the FPLMN list. If there are nonetworks remaining, then at step 320 GSM network selection algorithm asoutlined in Specification 23.122 (“GSM Network Selection”) commences. Ifthere are additional networks to test, then the method repeats beginningat step 5A and the next network on the list is checked as previouslydescribed.

If the network is not on the FPLMN list, then a check is made at step325 to see if it is on one of the two PPLMN lists. If not, then thenetwork is placed in the unknown network list 330, as described in FIG.6. If the network is on one of the PPLMN lists, a further check is madeat step 335 to see if it supports a data communication service. If itdoes not support the data communication service, or if the datacommunication service is unavailable, then at step 340 the network isplaced on the known voice-only list of networks maintained in memory ofthe mobile station. Processing then returns to step 5A to check foradditional networks. If the network does support the data communicationservice, then it will be added to the U-PPLMN list at step 370 andprocessing returns to step 5A.

Turning now to FIG. 6, the flowchart has one entry point from FIG. 5 asshown. Entry point 400 handles registering unknown networks that arefound during scanning. If an unknown network is detected, then the firsttest is to determine whether it supports data communication service atstep 405. If it does support the data communication service, e.g.GSM/GPRS, it is added to an ‘Unknown Voice-Data List’ in memory such asRAM 226 (FIG. 2) at step 410. Since it is a voice-data network, at step412 it is added at the bottom of the User PPLMN list (as low prioritysince it is unknown). If the unknown network is a voice-only network attested at step 405, then at step 415 the network is placed on an‘Unknown Voice-Only List’ which is also stored in memory. Once theunknown network is added to an unknown networks list, the mobile stationtests to see if there are any more networks to be tried at step 425. Ifthere are other networks to be tried, then the method continues at step5A in FIG. 5. If there are no remaining networks to be tried, then themethod ends and the GSM Network Selection at step 420 commences.

More on Rescanning. The network rescan timer is a timer that is startedwhen the camped-on communication network is not the home network. Thus,if the mobile station camps on a communication network other than thehome network, the rescan timer is started. When a timeout occurs, theselection technique initiates a search for the home network, selects andcamps on the home network if found, and resets the timer should the homenetwork not be found.

FIG. 7 is a flowchart which describes a rescanning method of the presentapplication. As described above in connection with FIGS. 5–6, the methodof FIG. 7 may be implemented in software on a mobile station. In step500 of FIG. 7, the mobile station detects a country or region change. Instep 505, it results in the mobile station camping on a voice-onlynetwork, which is neither the home network nor a known voice-datanetwork. After some time lapses, the rescan timer expires at step 515which triggers a rescan for new networks in the area at step 520. Therescanning process provides an opportunity for a mobile station to finda network that is known or offers better services to the mobile stationuser. A network offering better services could be considered in order ofdecreasing capability to be: a known voice and data network, a knownvoice-only network, an unknown voice-data network, and finally anunknown voice-only network.

For each network found, a test is made to see if the network is on theFPLMN list at step 525. If the network is on the FPLMN list, then a testis performed at step 530 to see if all networks have been retried. Ifthere are more networks to try in step 530, the testing continues.Otherwise, if there are no more networks to try, the rescan is stoppedand the rescan-timer is reset at step 535. If the network found was noton the FPLMN list, then a test is performed at step 540 to see if thenetwork is on one of the PPLMN lists. If it is not on one of the PPLMNlists, then a further test is performed at step 545 to see if it is adata-capable network. If the network is unknown and is not a datanetwork, then the method may return to step 530 to check for othernetworks. This is because an unknown voice-only network with bettersignal strength can be better the voice-only network already in use.

If the network is data-capable, however, then it falls into the categoryof an unknown data network which could potentially be better than anunknown voice network. To verify this, the mobile station tests at step555 to see if the currently camped-on network is an unknown voicenetwork such as a GSM network. If this is not the case, then the currentnetwork is as good as or better than the found network, so the methodreturns to step 530 to check if any other networks were found. If themobile station verifies that the current camped-on network is an unknownvoice-only network, then the newly discovered unknown data network willbe used in place of the current network, as indicated at step 560. Ifone of these operations fails, as determined at step 565, the methodwill return to step 530 to scan for other data networks. If the attachis successful, then the network is placed in the U-PPLMN list and thenetwork is used for communications 570.

Returning to step 540, if it is determined that the network is known inthe PPLMN list, the method then checks to see if the network supportsdata, at step 550. If the network does not support data, an extra checkis performed at step 555 to see if the current network is an unknownvoice only network, i.e. GSM, as described above. When a known GSMnetwork has been identified, it should be substituted for a currentunknown GSM network. If the current network is an unknown GSM network,or if the new network is a known data network like GSM/GPRS, then themobile station will attempt to attach to the new network and open a PDPcontext to the home APN at step 560. If the attach or PDP contextcreation fails, then the method returns to step 530 to check any othernetworks that were found. Otherwise, the network is accepted, added tothe user PPLMN list and used for communications at step 570.

FIG. 8 is a flowchart which describes an alternate rescanning method.Steps 500 through 520 are the same as those described in relation toFIG. 9. When arriving at step 520, however, the embodiment depicted inFIG. 8 returns to the method revealed in FIGS. 5–6 (“Goto 5A”),establishing a prioritized list which the GSM Network Selection will useto select a network. The method described in FIGS. 5–6 will then beperformed, providing a more desirable network for the mobile station.

Network Selection Using A Service Access List. FIG. 9 is a flowchartwhich describes an alternate method of providing for network selectionin a mobile station. In this method, conventional network selection isperformed in connection with conventional PLMN lists but thereafter theselection is cross-checked against other preferable networks (e.g. datacommunication available networks) which may be listed in a separate“service access list”. It is noted that separate service access listsmay be kept on a per region basis (e.g. per MCC) to improve performance.

In step 1100 of FIG. 9, the mobile station is registered with aparticular PLMN and operates in an idle mode where it camps on aparticular wireless channel of one of PLMN's base stations. If poor cellconditions exist, or if a better cell is available, then conventionalGSM network selection is performed in step 1102 in an attempt to pick anew PLMN. This step includes performing the scanning process andprioritized PLMN selection using conventional PLMN lists. If the PLMNselected in step 1102 is the home PLMN, or the same PLMN alreadyregistered with, then the mobile station continues to operate on thePLMN in step 1100 after resetting the rescan timer in step 1106 if fullcommunication services are still unavailable.

If a new PLMN is selected in step 1102, the newly selected PLMN issearched for within the service access list in step 1104. If the newPLMN is found in the service access list, then the mobile stationattempts to connect through the network to access a data communicationservice in step 1110. The data communication service may be, forexample, that service offered by the mobile station's home network. Step1110 may be performed more specifically by sending a “request forservice” packet to a server on the mobile station's home network. Ifunable to actually access the service, the PLMN is removed from theservice access list in step 1112 and the method continues at step 1108.The mobile station will know that the data service is unavailable when,for example, it receives a non-delivery notification or noacknowledgement from the home network server within a specified periodof time.

If the newly selected PLMN is not found in the service access list instep 1104, or after being unable to connect through a network andremoving the network from the service access list in steps 1110 and1112, then a PLMN listed in the service access list is searched forwithin the current scan list in step 1108. If the PLMN is found in thescan list, then the mobile station attempts to connect through thenetwork to access a data communication service in step 1110, asdescribed previously. The method may also be invoked beginning at step1108 when the rescan timer has expired in step 1126 and a new scan listin 1128 is generated.

If the PLMN in the service access list is not found in the current scanlist in step 1108, then in step 1114 the mobile station sorts the scanlist for those PLMNs that support the data communication service. Instep 1116, the mobile station then attempts to actually connect throughthe network to access a data communication service, for all of the PLMNsin the sorted scan list. If the mobile station can establish the dataconnection with the PLMN for the data communication service, it “passes”and the PLMN is added to the service access list in step 1120. If themobile station cannot establish the data connection in step 1116, it“fails” and the mobile station selects the most-capable network in step1118 as is conventional. If there is a tie between networks, the mobilestation selects the network having the strongest signal to break the tiein step 1122. After steps 1118, 1120, and 1122, the method continues atstep 1106 to set the rescan timer through a connector A 1124. Thedescription in relation to FIG. 11 ends.

More Generalized Approaches. In a more generalized approach, a mobilecommunication device provides several different features and functionswhich require associated network services. Advantageously, its networkselection technique takes into account the availability of all of theseservices. To illustrate, the mobile device may provide an end-user withfeatures offered via communication networks which include, but are notlimited to, a voice communication service, an electronic mail (e-mail)service, a short messaging service (SMS), an Internet access service, aprivate Intranet access service, a wireless application protocol (WAP)service, a local data facilitating service, a home data facilitatingservice, and application-specific data services such as a weatherservice, a horoscope service, and a stock market quotations service.Additional services may be distinguished by the relative qualitydifferences between otherwise similar services, for example, ahigh-speed Internet service versus a low-speed Internet service.

In the present approach, the mobile device identifies one or morecommunication networks available for communication within a geographiccoverage area. The mobile device may perform this step using aconventional scanning operation. Next, the mobile device identifies oneor more communication services made available by each one of thesecommunication networks. These communication services may be or includeany of the services listed above, or other suitable services. Eachcommunication network may have only a subset of communication servicesavailable for the mobile device. Preferably, the mobile deviceidentifies the availability of these services at least in part byactually attempting to access the service in the network.

Next, the mobile device selects communication networks in a prioritizedfashion based on the communication services that are made available byit. Preferably, the mobile device selects or gives first priority to acommunication network that makes available the best or the mostcommunication services for the mobile device. It is this network thatthe mobile device may register and operate with. If assigningpriorities, the mobile device preferably keeps a prioritized networklist of networks from the “best” to “worst”. The “best” network may bethe one that provides the greatest number of communication services forthe mobile device. Correspondingly, the “worst” network may be the onethat provides the least number of communication services.

Alternatively, the “best” network is the one that provides the greatestnumber of “preferred” communication services for the mobile device.Here, the one or more “preferred” communication services may bepredefined by the network, predefined by the mobile device manufacture(stored in the device's memory), or predefined by the end-user whoprograms such service priorities via the user interface. In anothervariation, each communication service is preassigned a relative weightvalue and a sum of relative weight values for available communicationservices in each network is calculated. Here, the “best” network is theone having the largest sum of weight values, and is kept at the top of aprioritized network list having the “best” to the “worst” networks.Additional weightings may be used as well for these decision-makingprocess, including success rate, data throughput rate (specified oractual), and cost.

As an extra feature in the mobile communication device, any of theinventive network selection methods described herein may be performedonly when the mobile device is in a special mode of operation. Thisspecial network selection mode may be called a “PREFERRED” networkselection mode, and may be provided in addition to the “AUTOMATIC” and“MANUAL” network selection modes of the mobile device. These differentmodes of network selection may be displayed on a visual display of themobile device so that an end-user may select one of them. Alternatively,the mode of network selection may be pre-programmed by the manufacturerof the mobile device.

As apparent, the above-described methodologies can be employed in theGSM-specific techniques previously described in relation to theflowcharts.

Summary/Advantages. Thus, methods and apparatus for selecting a cellularnetwork to provide one or more communication services for a mobilecommunication device have been described herein. A scanning operation isperformed by the mobile device to identify one or more communicationnetworks which support a voice communication service in a geographiccoverage area. The mobile device then determines which of thecommunication networks make a data communication service available forthe mobile device in the geographic coverage area. Advantageously, themobile device selects and registers with a communication network thatmakes the data communication service available over a network that failsto make the data communication service available. Preferably, the mobilecommunication devices operate in accordance with GSM (Global System forMobile) and GPRS (Generalized Packet Radio Service). Also preferably,the method is performed in connection with the creation of one or moreprioritized network lists. In this case, the mobile device assigns ahigher priority in the prioritized network list to a communicationnetwork that makes the data communication service available over acommunication network that does not make the data communication serviceavailable.

The method may be more generalized to involve a mobile communicationdevice which identifies one or more communication networks available tofacilitate mobile communications with the mobile device in a geographiccoverage area; identifies one or more communication services that areactually made available to the mobile device in each network; determineswhich network provides the best communication services for the mobiledevice based at least in part on the identified availability of servicesin each network; selects or assigns priority to the network that isdetermined to provide the best services for the mobile device; andregisters with the selected or prioritized network. The communicationservices which may be made available by the networks include, but arenot limited to, a voice communication service, an electronic mail(e-mail) service, a short messaging service (SMS), an Internet accessservice, a private Intranet access service, a wireless applicationprotocol (WAP) service, a local data facilitating service, a home datafacilitating service, and application-specific data services such as aweather service, a horoscope service, and a stock market quotationsservice.

Advantageously, the above-described methods allow a mobile device toautomatically select the best network to provide mobile communicationsfor it. Services available for any given device and network may bemaximized without user intervention. The capabilities of the devices canbe continually improved as an end-user moves to ever-richer serviceareas. Also, several methods provide for the continued use ofconventional methods and PPLMN lists. Finally, the methods also do notrequire active updates from the network to manage connectionpreferences.

It will be appreciated that the above description relates to preferredembodiments by way of example only. Many variations thereof will beobvious to knowledgeable in the field to which the invention pertains,and such variations are within the scope of the invention as describedand claimed, whether or not expressly described. For example, althoughthe detailed description has strictly used the term “network” in contextof the inventive methods (which presumes substantial homogeneity insideeach network), the invention also broadly includes selecting betweensub-sections of networks including network subnets and even individualcells. As another example, although embodiments of the invention haveplaced an emphasis on GSM and GSM/GPRS networks, and voice anddata-capable mobile stations, it should be appreciated that theinvention is not limited to such networks, mobile stations, andservices. The invention is applicable to other systems in which mobilestations are enabled for communication services available to differentextents. Finally, although the mobile device oftentimes identifies aplurality of communication networks available within its geographiccoverage area, it may sometimes identify only a single available networkwith which to act upon; this understanding should not in any way limitthe interpretation of the claims.

1. In a mobile communication device, a method of selecting a cellularnetwork for communications comprising the acts of: performing a scanningoperation to identify one or more cellular networks in a geographiccoverage area; identifying which of a plurality of communicationservices, if any, are made available by each cellular network for themobile communication device; determining which cellular network makesthe largest number of preferred communication services available to themobile communication device; and assigning network selection priority tothe cellular network that makes the largest number of preferredcommunication services available to the mobile communication device. 2.The method of claim 1, wherein the plurality of communication servicescomprises at least one data communication service and the preferredcommunication services are predefined in memory of the mobilecommunication device.
 3. The method of claim 1, wherein the plurality ofcommunication services comprise at least one of an electronic mail(e-mail) service and an Internet access service.
 4. The method of claim1, wherein the act of identifying which communication services are madeavailable by a cellular network comprises the further acts of:attempting to access a communication service over the communicationnetwork; and being granted or unable to access the communication serviceover the communication network.
 5. The method of claim 1, wherein theact of assigning network selection priority comprises the further actof: creating or modifying a prioritized network list stored in memory ofthe mobile communication device.
 6. In a mobile communication device, amethod of selecting a communication network comprising the acts of:identifying one or more communication networks available to facilitatemobile communications with the mobile communication device in ageographic coverage area; identifying one or more communication servicesthat are made available with each communication network; determiningwhich communication network provides the best communication services forthe mobile communication device based at least in part on the identifiedavailability of communication services in each communication network, bydetermining that the communication network has a greater or equal numberof communication services available to the mobile communication devicethan any other identified communication network; and selecting orassigning priority to the communication network that is determined toprovide the best communication services for the mobile communicationdevice; and registering with the selected or prioritized communicationnetwork.
 7. The method of claim 6, wherein the act of identifying one ormore communication services that are made available with eachcommunication network is based on an attempt to access the one or morecommunication services in each communication network.
 8. The method ofclaim 6, wherein the communication services comprise preferredcommunication services of the mobile communication device which arepredefined in memory.
 9. The method of claim 6, wherein eachcommunication service is assigned a weight value, and wherein the act ofdetermining which communication network provides the best communicationservices for the mobile communication device comprises the further actsof: for each communication network, calculating a sum of weight valuesof all of the communication services made available in the communicationnetwork; and determining that the communication network has a sum ofweight values that is greater than or equal to that of any identifiedcommunication network.
 10. The method of claim 6, wherein the act ofassigning priority comprises the further act of: creating or modifying aprioritized network list stored in memory of the mobile communicationdevice.
 11. The method of claim 6, wherein the communication servicescomprise one or more data communication services.
 12. The method ofclaim 6, wherein the communication services comprises a plurality of thefollowing services: a voice communication service; an electronic mailservice; a short messaging service; an Internet access service; aprivate Intranet access service; and a wireless application protocol(WAP) service.